View source for 1zyn


==Oxidized structure of the N-terminal domain of Salmonella typhimurium AhpF==
<StructureSection load='1zyn' size='340' side='right'caption='[[1zyn]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1zyn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhimurium Salmonella enterica subsp. enterica serovar Typhimurium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZYN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ZYN FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.3&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1zyn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1zyn OCA], [https://pdbe.org/1zyn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1zyn RCSB], [https://www.ebi.ac.uk/pdbsum/1zyn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1zyn ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AHPF_SALTY AHPF_SALTY] Serves to protect the cell against DNA damage by alkyl hydroperoxides. It can use either NADH or NADPH as electron donor for direct reduction of redox dyes or of alkyl hydroperoxides when combined with the AhpC protein.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/zy/1zyn_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1zyn ConSurf].
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== Publication Abstract from PubMed ==
The flavoprotein component (AhpF) of Salmonella typhimurium alkyl hydroperoxide reductase contains an N-terminal domain (NTD) with two contiguous thioredoxin folds but only one redox-active disulfide (within the sequence -Cys129-His-Asn-Cys132-). This active site is responsible for mediating the transfer of electrons from the thioredoxin reductase-like segment of AhpF to AhpC, the peroxiredoxin component of the two-protein peroxidase system. The previously reported crystal structure of AhpF possessed a reduced NTD active site, although fully oxidized protein was used for crystallization. To further investigate this active site, we crystallized an isolated recombinant NTD (rNTD); using diffraction data sets collected first at our in-house X-ray source and subsequently at a synchrotron, we showed that the active site disulfide bond (Cys129-Cys132) is oxidized in the native crystals but becomes reduced during synchrotron data collection. The NTD disulfide bond is apparently particularly sensitive to radiation cleavage compared with other protein disulfides. The two data sets provide the first view of an oxidized (disulfide) form of NTD and show that the changes in conformation upon reduction of the disulfide are localized and small. Furthermore, we report the apparent pKa of the active site thiol to be approximately 5.1, a relatively low pKa given its redox potential (approximately 265 mV) compared with most members of the thioredoxin family.

Oxidized and synchrotron cleaved structures of the disulfide redox center in the N-terminal domain of Salmonella typhimurium AhpF.,Roberts BR, Wood ZA, Jonsson TJ, Poole LB, Karplus PA Protein Sci. 2005 Sep;14(9):2414-20. PMID:16131664<ref>PMID:16131664</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella enterica subsp. enterica serovar Typhimurium]]
[[Category: Jonsson TJ]]
[[Category: Karplus PA]]
[[Category: Poole LB]]
[[Category: Roberts BR]]
[[Category: Wood ZA]]